* Implement the LearningRateScheduler callback
* Add missing files
* Cleanup
* Formatting
* Remove test util for building model
* Initial implementation of ReduceLROnPlateau
* Remove unused test variables
* Tests for ReduceLROnPlateau
* Improve docstrings
* Review comments
* Implement the LearningRateScheduler callback
* Add missing files
* Cleanup
* Formatting
* Remove test util for building model
* Remove unused test variables